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In this paper, we study the effect of moving bottlenecks on traffic flow. The full velocity difference (FVD) model is extended to the traffic flow on a two-lane highway, and new lane changing rule is proposed to reproduce the vehicular lane changing behavior. Using this model, we derive the fundamental current-density diagrams for the traffic flow with the effect of moving bottleneck. Moreover, typical time-space diagram for a two-lane highway shows the formation and dissipation of a moving bottleneck. Results demonstrate that the effect of moving bottleneck enlarges with the increase of traffic density, but the effect can be reduced by increasing the maximum velocity of heavy truck. The effects of multiple moving bottlenecks under different conditions are investigated. The effect becomes more remarkable when the coupling effect of multiple moving bottlenecks occurs. 相似文献
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很多学生对数学学习投入的热情正在日益减退,一方面是因为随着数学学习的不断深入,学生所要学习的知识变得复杂和抽象,另一方面,在一定程度上学生学习数学的方式是被动地听讲、练习、记忆和考试,多数学生把上数学课作为一种精神负担,小是“我要学”而是“要我学”. 相似文献
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合成了十六种新的拟除虫菊酯类化合物,其通式为:药理实验表明:只有含Y=3-苯氧基或3,4-亚甲二氧的化合物对粘虫有较强的触杀作用。 相似文献
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The femtosecond laser pulses reflected from the self-induced plasma mirror(PM) surface are characterized. More than two orders of magnitude improvement on intensity contrast both in nanosecond and picosecond temporal scales are measured. The far-field distribution, i.e., focusability, is measured to degrade in comparison with that without using a PM. Experiments on proton accelerations are performed to test the effect of the balance between degraded focusability and increased reflectivity. Our results show that PM is an effective and robust device to improve laser contrast for applications. 相似文献
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丁腈羟聚氨酯/聚环氧树脂互穿网络高聚物的研究 总被引:3,自引:0,他引:3
本文用同步法合成了丁腈羟聚氨酯/聚环氧树脂(PU/PE)体系的互穿网络高聚物(IPN),研究了各种因素对其形态和玻璃化转变行为的影响,并用扭辫及扭摆(TPA)在-100℃-+150℃温度区间内,测试全部试样的动态力学谱。结果表明,PU/PE是不相容体系,在电镜片上呈现细胞状结构(400-800Å)。由于两组份网络互穿,发生“强迫互容”,使Tg内移,通过调整组份比和加不同扩链剂等能提高阻尼值,加宽Tg转变区。 相似文献
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